Science briefs: Blood type may affect heart risk

BLOOD TYPE MAY AFFECT HEART RISK

Potentially good news for the 45 percent of Americans who have Type O blood: Researchers said that those people appear to have a slightly lower risk of developing heart disease than those with Type A, B or AB blood.

Dr. Lu Qi of the Harvard School of Public Health analyzed heart disease risk in two large, multi-decade health studies -- reviewing data collected from 62,073 women who participated in the Nurses' Health Study, which was launched in 1976, and from 27,428 men who took part in the Health Professionals Follow-up Study, launched in 1986.

Qi and his colleagues found that participants with type AB blood had the largest heart disease risk -- 20 percent greater than that of people with Type O blood. (The team calculated that the incidence of heart disease was 125 cases per 100,000 person-years.) Type B had an 11 percent greater risk, and type A had an 8 percent greater risk, the scientists reported.

The researchers noted that non-O individuals have higher levels of two proteins involved in clotting and atherosclerosis -- and that people with Type A blood, in particular, have been reported to have higher levels of serum total cholesterol and LDL (bad) cholesterol. The research appeared in the journal Arteriosclerosis, Thrombosis and Vascular Biology, which is published by the American Heart Association.

TEST MAY AID HEART ATTACK DIAGNOSIS

Doctors may be able diagnose a heart attack in one hour using a new approach that could save time, money and crowding in emergency rooms, researchers said.

Using more-sensitive screening technology to detect changes in cardiac troponin, a substance in the blood tested for evidence of heart attack, and inputting the data into an algorithm, doctors were able to determine whether a heart attack had occurred in 77 percent of patients within an hour of arriving at the hospital with chest pain, according to research published in the Archives of Internal Medicine.

About 10 percent of all emergency room consultations are for heart attack symptoms, the researchers said. Limitations in older tools used to read troponin can delay heart attack diagnosis for as long as six hours and contribute to overcrowding in the emergency room, the authors said. The more-sensitive blood tests, however, aren't yet available in clinical practice in the United States.

A NEW APPROACH ON CROHN'S DISEASE

Seattle researchers are seeking to cure severe Crohn's disease by giving patients a new immune system. The newly approved clinical trial will take a closer look at a side effect of bone-marrow transplantation that researchers at the Fred Hutchinson Cancer Research Center noticed years ago: A handful of leukemia patients given donor marrow cells were also cured of their Crohn's disease, a chronic intestinal inflammation.

The idea behind the study is simple: "It's swapping out an old, diseased immune system for a new immune system, which we hope -- and our research would support -- will take care of the Crohn's disease," said Dr. George McDonald, a transplant researcher and gastroenterologist.

The Crohn's & Colitis Foundation of America estimates that 700,000 Americans live with Crohn's disease, which can cause pain, fever, diarrhea and weight loss. For most, medications control the disease, but a small fraction has found no relief. If this trial is successful in patients with severe Crohn's, McDonald said, he hopes to be able to broaden the criteria for others with Crohn's. "This is one step toward offering this as the definitive therapy for more patients with this disease."